Molecular siting in the liquid-phase adsorption of alkane and aromatic mixtures in MFI zeolites: An experimental and molecular modeling study

Results from experiment and molecular simulation are presented for liquid-phase adsorption in MFI zeolites. Excellent agreement between experiment and simulation is observed for mixtures of aromatics and mixtures of linear alkanes. The siting of molecules within the pores predicted by molecular simulation can explain experimentally-observed features of adsorption. Under liquid-phase adsorption conditions, the pores are quite full of molecules. Efficient packing for long chain molecules requires molecules to bend and "cross" each other at the channel intersections. Advanced biasing techniques and identity-swap moves are used to converge the GCMC simulations in reasonable times. The results indicate that if force fields are available that predict single-component adsorption in agreement with experiment then GCMC can quantitatively predict mixture behavior over a wide range of conditions.